> The theory is that varroa mites will never go into a
> queen cell. Is this a correct assumption?

Yes, this is true.  Queens hatch in 16 days, whereas the varroa life cycle
requires over 20 days.  Workers hatch in 21 days, drones in 23.  Varroa
prefer drones as the drones developement time is most in synch with their
own and they are most successful reproducing in drone cells.  Workers'
developement is next in line with Varroa (I do not recall the exact time for
Varroa cycle and do not have texts on hand).  However, queen developement is
simply too quick for Varroa to be interested in inhabiting a queen cell.  I
know of no documented cases of Varroa in queen cells.

Sincerely,
Aaron Morris